<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="http://www.baidu.com">
  用户名：<input type="text" name="username" readonly maxlength="4"  value="abc" placeholder="请输入用户名"><br>
  用户名：<input type="password" name="password" placeholder="请输入密码"><br>
  性别： <input type="radio" name="gender" value="m" checked id="r1">
  <label for="r1">男</label>
  <input type="radio" name="gender" value="w" id="r2">
  <label for="r2">女</label><br>
  兴趣爱好：<input type="checkbox" name="hobby" value="cy">抽烟
  <input type="checkbox" name="hobby" value="hj">喝酒
  <input type="checkbox" name="hobby" value="tt">烫头<br>
  生日：<input type="date" name="birthday"><br>
  靓照：<input type="file" name="pic"><br>
  所在地：
  <select name="city">
    <option value="sh">上海</option>
    <option value="bj">北京</option>
    <option selected>杭州</option>
  </select><br>
  <input type="submit" value="注册">
  <input type="reset">
  <input type="button" value="自定义按钮">
  <hr>
  <button type="submit">注册</button>
  <button type="reset">重置</button>
  <button type="button">自定义按钮</button>
</form>
</body>
</html>